170421 has 4 divisors (see below), whose sum is σ = 227232. Its totient is φ = 113612.

The previous prime is 170413. The next prime is 170441. The reversal of 170421 is 124071.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 124071 = 3 ⋅41357.

It is a cyclic number.

It is not a de Polignac number, because 170421 - 2³ = 170413 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 170421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (170441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28401 + ... + 28406.

It is an arithmetic number, because the mean of its divisors is an integer number (56808).

2¹⁷⁰⁴²¹ is an apocalyptic number.

It is an amenable number.

170421 is a deficient number, since it is larger than the sum of its proper divisors (56811).

170421 is an equidigital number, since it uses as much as digits as its factorization.

170421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56810.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 170421 is about 412.8207843605. The cubic root of 170421 is about 55.4422742061.

Adding to 170421 its reverse (124071), we get a palindrome (294492).

The spelling of 170421 in words is "one hundred seventy thousand, four hundred twenty-one", and thus it is an iban number.